FILE - In this Tuesday, March 17, 2020 file photo British Prime Minister Boris Johnson gestures as he gives a press conference about the ongoing situation with the COVID-19 coronavirus outbreak inside 10 Downing Street in London. British Prime Minister Boris Johnson has been admitted to a hospital with the coronavirus. Johnson’s office says he is being admitted for tests because he still has symptoms 10 days after testing positive for the virus.(AP Photo/Matt Dunham, File)

British Prime Minister Boris Johnson has been moved to the intensive care unit of a London hospital after his coronavirus symptoms worsened.

Johnson’s office says Johnson is conscious and does not require ventilation at the moment.

Johnson was admitted to St. Thomas’ Hospital late Sunday, 10 days after he was diagnosed with COVID-19.

“Over the course of this afternoon, the condition of the Prime Minister has worsened and, on the advice of his medical team, he has been moved to the Intensive Care Unit at the hospital,” his office said in a statement.

It said Johnson has asked Foreign Secretary Dominic Raab to deputize for him.

Johnson’s fiancee Carrie Symonds, 32, revealed Saturday that she spent a week with coronavirus symptoms, though she wasn’t tested. Symonds, who is pregnant, said she was now “on the mend.”

The government said Sunday that almost 48,000 people have been confirmed to have COVID-19 in the U.K., and 4,934 have died.

Johnson replaced Theresa May as prime minister in July and won a resounding election victory in December on a promise to complete Britain’s exit from the European Union. But Brexit has been overshadowed by the coronavirus pandemic sweeping the globe.

Johnson’s government was slower than those in some European countries to impose restrictions on daily life in response to the pandemic, but Britain has been effectively in lockdown since March 23.

Several other members of Johnson’s government have also tested positive for the virus, including Health Secretary Matt Hancock and junior Health Minister Nadine Dorries. Both have recovered.

News of Johnson’s admission to hospital came an hour after Queen Elizabeth II made a rare televised address to the nation, urging Britons to remain “united and resolute” in the fight against the virus.

Drawing parallels to the struggle of World War II, the 93-year-old queen said that “while we may have more still to endure, better days will return: we will be with our friends again; we will be with our families again; we will meet again.”